中文摘要：

根据喷嘴长度和入口边界条件,将液体火箭发动机气液同轴式喷嘴简化为4类：四分之一波长闭管、二分之一波长闭管、四分之一波长开管和二分之一波长开管。采用线性声学理论对喷嘴入口开口率的声学抑制影响进行了研究,得到了入口开口率声学影响规律。结果表明：在标准长度和最佳长度2种条件下,开口率对喷嘴抑制能力的影响差别很大。合理选择开口率和喷嘴长度能够有效提高喷嘴抑制能力。研究结果可为喷嘴长度和入口射流条件优化设计、燃烧室声学振荡抑制提供参考。

英文摘要：

According to the length and the inlet boundary conditions of injector,the gas-liquid coaxial injectors of liquid rocket engine are simplified into four categories： 1 /4 wavelength closed tube,1 /2 wavelength closed tube,1 /4 wavelength open tube and 1 /2 wavelength open tube. Linear acoustics is adopted to analyze the influence of the inlet opening ratio on the acoustic damping capability of the injector in order to obtain the law of the acoustic influence of opening ratio. It is found that the inlet opening rate has a very different effect on the damping capability of the injector under the conditions of standard length and optimal length. The damping capability can be greatly improved if the inlet opening rate and the length of the injector are chosen reasonably. The research results can provide reference for the optimum design of the length and inlet jet of the injectors,and acoustic damping of the combustion chamber.